A primary goal in the harvesting of hay is to dry the hay as soon as possible and remove it from direct exposure to sunlight. The hay must be dried before storage to avoid the problems of mold and spontaneous combustion. Exposing the cut hay to sunlight longer than is required to adequately dry it, however, results in unacceptable deterioration of the protein level (and therefore nutritive value) of the hay.
Typically, hay is harvested into approximately five foot swaths along the ground, and is exposed to sunlight for the initial stage of the drying process. The swaths of hay are then raked into narrow windrows to remove most of the hay from direct contact with the moist ground. The windrow enhances more air circulation within the hay, thereby hastening the drying process.
Rakes have long been used for forming swaths into windrows. Early rakes included relatively movable support frame members to control or adjust operational positions of the rake. Examples of such rake implements are disclosed in U.S. Pat. Nos. 2,925,702, 2,982,081 and 3,108,424.
Improvements in rake implements are disclosed in U.S. Pat. Nos. 4,077,189 (to Hering) and 4,245,458 (to Smith), disclosing plural rakes and telescoping adjustment structures for adjusting the width and size of windrows and the spacing of the rakes. The twin rakes disclosed in the patent to Hering include pivot hinges for the rake support structure to permit the rakes to float and to raise the outer end of the rakes into a transport position.
U.S. Pat. No. 4,723,401 (to Webster et al.) discloses a raking implement wherein a 4-bar linkage, including a hydraulically operated control link, enables an operator to steer wheels that support frame arms. A stabilizer mechanism is provided to limit the extent of pivotal movement of the frame arms. U.S. Pat. Nos. 4,183,198 (to Sligter) and 4,214,428 (to Caraway) disclose other rakes for forming single large windrows for baling hay into large roll-type bales. These rakes have a V-shape formed by two groups of rakes attached to a frame. The relative position of the groups may be varied.
U.S. Pat. No. 4,231,218 (issued to Delgado and assigned to Vicon Espana S.A.) discloses a rake for matching the unevenness and slopes of the ground. The rake has a wheeled main frame, a subframe formed by relatively independently pivotable arms fastened to the main frame, two board supports pivotally connected with the subframe, and rake boards arranged on the board supports.
Another improvement of the agricultural rake is represented by the Bi-Fold Hay Rake disclosed in U.S. Pat. No. 4,947,631 (to Kuehn). The Kuehn rake includes two rake supporting frames attached to one transport frame. The supporting frames are pivotally attached to the transport frame at the rear end thereof and are supported by a pair of extensible support braces.
While the above cited patents represent improvements and advances in agricultural raking implements, there are several inadequately addressed or unaddressed problems. First, as the cost of raising crops increases, it is of paramount importance to increase the efficiency of agricultural activities. Efficiency can be increased by reducing the number of passes through a field required to gather hay like crops into windrows. Thus, it is an object of the present invention to increase efficiency by providing a rake implement that enables gathering a wider swath of crop material in one pass.
A rake designed to gather wider swaths requires a frame for supporting individual rake components adequately and adjustably, yet without involving a complicated, interengaging plurality of support frame members. Additionally, it would be helpful to be able to control a rake without requiring complicated control or manipulation systems for selecting working positions.
Another difficulty is adequately isolating the rake implement from the irregularities and roughness of the ground or field surface on which it is being used. This problem is compounded by the need to gather the valuavle crop as completely as possible, while providing a means for preventing damage to the rake caused by irregular ground. Thus, it is an object of the present invention to provide an improved wheel rake that increases efficiency and minimizes maintenance cost.
Additional unmet needs include the need for a structurally uncomplicated rake implement so that the owner easily may perform routine maintenance. The implement should be able to be drawn or transported safely and easily to and from fields, along standard highways and through relatively narrow gates and building doors. The implement should be able to be operated conveniently and easily by a minimum number of operational control levers or devices.
It is clear that there is a need for an efficient, simple and durable rake that substantially improves the efficiency of gathering field crops prior to baling them for storage, minimizes maintenance problems and provides for safe, efficient use and transport.